willSetnewValue

The willSetnewValue is a property observer in Swift that is called immediately before a value is set on a property. This observer is invoked for any property that has the willSet attribute specified. When willSetnewValue is called, it passes the new value as a parameter, which is typically named newValue by convention. This parameter allows you to access the value that is about to be assigned to the property.

The primary purpose of willSetnewValue is to allow for custom logic to be executed just before a property's value changes. This can include tasks such as validating the incoming value, updating other related properties, or logging the change. It's important to note that within the willSetnewValue observer, you cannot directly modify the property itself, as this would lead to an infinite loop. Instead, you should perform any necessary modifications to other properties or external state based on the provided newValue.

willSetnewValue is paired with didSetnewValue, another property observer. While willSetnewValue is called before the value is set, didSetnewValue is called immediately after the new value has been stored. Both observers are useful for managing property changes and ensuring the consistent state of your data model. They are declared using the `willSet` keyword followed by a trailing closure that receives the new value.